In factories and the like, article accommodating cases that are molded from plastic are used to accommodate articles for storage and shipping.
Furthermore, such article accommodating cases also include cases equipped with connecting means that connect the cases to each other so that there is no collapse of the load when these cases are placed side by side on pallets, and are further stacked and transported by means of a forklift.
For example, in the article accommodating case (plastic container) disclosed in Japanese Patent Application Laid-Open No. 7-52950, permanent magnets are attached to the side surfaces of the case as connecting means, and adjacent cases are connected to each other by the magnetic force of these magnets.
Furthermore, in the article accommodating case (container) disclosed in Japanese Patent Application Laid-Open No. 9-169339, connecting fittings are attached to the edge parts of the upper opening of the case so that these connecting fittings are free to pivot, and respective anchoring parts that are caused to protrude from these connecting fittings are caused to engage with the upper edges and connecting fittings of mating cases.
However, in both of these cases described in the abovementioned Japanese patent references, permanent magnets or connecting fittings that are separate parts must be attached to the case main body, so that the cost is correspondingly increased; furthermore, the attached permanent magnets or connecting fittings must be removed at the time of recycling, which is inconvenient.
Furthermore, although commonly used article accommodating cases molded from plastic have a considerable weight in a state in which articles are accommodated in the case, and are therefore not blown about by the wind when such cases are placed in outdoor locations that are exposed to the wind, these cases do tend to be blown about by the wind when the cases are in an empty state; accordingly, when such cases are placed in outdoor locations, it is necessary to place weights on the cases, or to connect the cases by means of ropes or the like, so that the cases are not blown about by the wind.
Furthermore, when cases that are placed in outdoor locations are exposed to rain, water accumulates inside the cases, so that an operation that removes water from the cases is essential at the time of use. Moreover, especially in instances where articles are accommodated inside the cases, an operation that removes only the water from the insides of the cases is an extremely difficult operation, so that the working characteristics during use are poor.
Furthermore, in instances where empty cases are stored in a stacked state, the peripheral edges of the bottom surfaces of the cases in the upper tiers are placed on the upper edges of the openings of the cases positioned below in the same manner as when articles are accommodated in the cases; accordingly, the stacked cases are bulky, and require a large storage space.
Moreover, since common cases have a shape in which the entire undersurface of the bottom of the case contacts the ground, the ground contact state deteriorates in cases where the central portion of the bottom of the case sags downward as a result of changes over time caused by the weight of the accommodated articles, and there have been instances in which such cases have an unstable position that shows wobbling when the case is placed on a flat surface.
The present invention was devised in light of the various problems seen in the abovementioned conventional general article accommodating cases; it is an object of the present invention to provide an article accommodating case which makes it possible to obtain (in an inexpensive manner) cases that allow adjacent cases to be connected to each other, which makes it possible to fasten the cases in a stable manner, which shows no accumulation of rain water or the like inside the cases, which shows no problems of bulkiness when empty cases are stored, and which guarantees secure ground contact even if the central portion of the bottom wall of the case should sag downward as a result of changes over time.